This invention relates to stabilized cosmetic products, especially antiperspirant and/or deodorant products which may include an antiperspirant active ingredient and a low water component which provides better efficacy and stability without compromising aesthetics. The compositions are emulsions made with an external (or oil) phase and an internal phase which contains the active ingredient. These emulsions may be used to form gel, soft solid or roll-on products.
A large variety of antiperspirant and/or deodorant formulations have been described in the patent literature and/or have been made commercially available. These products have included suspension as well as emulsions. Also various physical forms may be used such as solids (for example, wax and gel sticks), semi-solids (for example, gels and creams), liquids (for example, roll-on products) and sprays (both aerosol and non-aerosol). In recent years a strong emphasis has been placed on improving both the performance and the aesthetics of these products. One of the particular problems is trying to obtain an emulsion product that has efficacy comparable to suspension products. A second problem is the stabilization of emulsion products to achieve a product that is shelf stable, but which releases an active ingredient in a timely manner.
With regard to emulsions, U.S. Pat. No. 4,673,570 to Soldati describes uniform, clear gelled antiperspirant compositions, free of waxes wherein the emulsions comprise in combination a volatile silicone fluid, a silicone emulsifier (such as a mixture of cyclomethicone and dimethicone copolyol), a destabilizing auxiliary emulsifier, water, a non-volatile emollient (such as C10-C20 alkyl fatty esters and ethers), linear silicone fluids, a coupling agent (such as low molecular weight alcohols and glycols), an active antiperspirant component and other ancillary agents.
U.S. Pat. No. 5,008,103 to Raleigh et al describes water-in-oil antiperspirant emulsions having a discontinuous polar phase containing water and optionally containing an emulsifier with a hydrophilic-lipophilic balance (HLB value) greater than 8, and a volatile silicone continuous phase with a dimethicone copolyol emulsifier. The HLB parameter is a well known parameter the calculation of which is disclosed and explained in numerous references. For nonionic surfactants, data obtained by actual analysis is usually a more accurate measure of HLB values (rather than theoretical determinations). For purposes of this invention it is intended that either the actual or theoretical HLB value may be used as the basis for selection. U.S. Pat. No. 5,401,870 to Raleigh et al and U.S. Pat. No. to 5,292,503 to Pereira et al describe similar subject matter.
U.S. Pat. No. 5,216,033 to Pereira et al describes a transparent water-in-oil emulsion containing a silicone phase with a dimethicone copolyol and an aqueous phase containing a refractive index xe2x80x9ctransparency structurantxe2x80x9d to produce a refractive index matched clear emulsion. The transparency structurant is a C3-C8 polyhydric alcohol.
U.S. Pat. No. 5,599,533 to Stepniewski et al describes the use of silicone elastomer in an aqueous water-in-oil emulsion, but does not describe a clear emulsion.
U.S. Pat. No. 5,989,531 describes a liquid composition made with (a) an active phase comprising a selected glycol, a nonionic emulsifier having an HLB value greater than 8 and an antiperspirant and/or deodorant active; and (b) a silicone phase made with one or more of a dimethicone copolyols having an HLB less than 7 and nonionic emulsifiers having an HLB greater than 7, wherein the silicone phase has at least 10% silicone and the ratio of the silicone phase to he active phase is in the range of 1:1-1:4. Optional ingredients include the use of non-volatile silicones, volatile silicones and organic emollients.
U.S. Pat. No. 6,010,688 discloses the use of polyhydric alcohols to improve the stability and efficacy of antiperspirant formulations, particularly antiperspirant gels.
U.S. Pat. No. 5,955,065 discloses antiperspirant gel compositions containing soluble calcium salts. These compositions contain an aluminum or aluminum-zirconium antiperspirant salt and a water soluble calcium salt, both of which are suspended in a dermatologically acceptable anhydrous carrier vehicle. The present invention also embraces a method of inhibiting or reducing perspiration by topically applying an effective amount of such an antiperspirant composition to the skin.
U.S. Pat. No. 5,925,338 discloses a clear antiperspirant or deodorant gel composition which exhibits reduced staining while retaining excellent aesthetic attributes and efficacy. The oil phase comprises about 10 to 25% of the composition and contains a silicone oil and a polyether substituted silicone emulsifying agent. The silicone oil comprises a mixture of a non-volatile silicone, preferably a non-volatile linear silicone, and a volatile linear silicone. It has been found that reducing the amount of non-volatile silicone in the known gel composition to a relatively low level (e.g. below about 5%) and adding an amount of volatile linear silicone to the composition (e.g. above about 2%, preferably above about 5%) substantially improves the non-staining properties of the composition.
U.S. Pat. No. 5,623,017 discloses a clear silicone gel cosmetic composition with a water-containing internal phase. The silicone emulsifiers discussed are non-polymeric ethoxylated bis-trisiloxanes.
U.S. Pat. No. 6,007,799 discloses a clear cosmetic gel composition in the form of a water-in-oil emulsion, comprising (a) a water-based phase comprising water, a cosmetically active ingredient, and at least one coupling agent; and (b) an oil-based phase comprising a material having a refractive index in the range of 1.40-1.50, silicone fluids and an alkoxylated, alkyl substituted siloxane surface active agent (e.g., dimethicone copolyol). The composition has a refractive index in a range of 1.4026 to 1.4150. Where the cosmetically active ingredient is an antiperspirant active ingredient, the composition can be an antiperspirant gel (for example, soft gel) composition. In the refractive index range of the present invention, increased amounts of, for example, antiperspirant active ingredient, and other high-refractive-index materials providing cosmetic benefits, can be incorporated in the water and oil phases of the composition while still achieving a clear composition. The composition can also include polypropylene glycols (for example, tripropylene glycol), as part of the water-based phase, to provide a composition having reduced tackiness and reduced whitening (decreased residue); this composition is also mild.
U.S. Pat. No. 5,587,173 discloses a clear gel-type cosmetic product which has a viscosity of at least about 50,000 centipoise (cps) at 21xc2x0 C., and includes an emulsion with an oil phase and a water phase that includes an incorporated active ingredient. The refractive indices of the water and oil phases match to at least 0.0004, the refractive index of the product is about 1.4000, and the product clarity is better than thirty NTU. These formulas contain 75-90% dispersed active phase. See also U.S. Pat. No. 4,021,536: which describes magnesium-zirconium complexes useful as antiperspirants; and U.S. Pat. No. 5,463,098 which describes clear antiperspirant gel stick and method for making same.
U.S. Pat. No. 3,979,510 describes aluminum-zirconium antiperspirant systems with complex aluminum buffers, including the use of various divalent metal ions in aluminum-zirconium antiperspirant formulations.
U.S. Pat. No. 4,980,156 discloses improved dry-feeling antiperspirant compositions which comprise an aqueous solution of an astringent emulsified in a volatile silicon fluid. The emulsion is stabilized by using a combination of a long-chain alkyl modified polysiloxane-polyoxyalkylene copolymer and an organic surfactant having an HLB value from 8 to 18.
U.S. Pat. No. 4,673,570 discloses uniform, clear gelled antiperspirant compositions, free of waxes and conventional gelling agents. The gel emulsions comprise, in combination, a volatile silicone fluid, a silicone emulsifier, a destabilizing auxiliary emulsifier, water, a non-volatile emollient, a coupling agent, an active antiperspirant component and ancillary agents.
U.S. Pat. No. 5,454,026 discloses a clear antiperspirant gel which is made by combining (a) an astringent compound having a refractive index of 1.48 to 1.53 which is an antiperspirant salt in the form of (i) a tray dried compound, (ii) an encapsulated salt, or (iii) a solvent solution of a salt compound; and (b) a clear anhydrous organic oil-free gel formed with 12-hydroxystearic acid as the gelling agent and a blend of aromatic containing silicone fluid and volatile silicone fluids.
U.S. Pat. No. 5,587,153 broadly discloses clear antiperspirant gels with a refractive index of 1.3975 to 1.4025 and a viscosity of 50,000-200,000 centipoise which are emulsions having 75-90% of a water phase.
U.S. Pat. No. 5,563,525 also discloses clear antiperspirant gels having a viscosity of at least 50,000 centipoise and a clarity better than 50 NTU which are emulsions having 75-90% of a water phase.
Historically, suspension products such as sticks have exhibited better efficacy than emulsion products. Previous attempts have not successfully overcome the problems of improving efficacy and achieving satisfactory formation of emulsions. Thus, it is an object of this invention to provide improved emulsions containing 0.5-15% water which exhibit improved efficacy which efficacy is comparable to that achieved in suspension products and, at the same time, have a stability profile that allows for satisfactory stability on the shelf. Another issue is the formation of emulsions which are stable on the shelf but which destabilize sufficiently after application to a skin surface so as to release an efficacious amount of an active ingredient. Thus, it is an object of the present invention to provide emulsions with those characteristics. It is also an object of this invention to provide gel or soft solid compositions which can, if desired, be formed into clear compositions. It is still another object of this invention to provide compositions that can, if desired, be formed into clear compositions without the use of microemulsions.
This invention relates to a low water, cosmetic composition comprising (a) 15-33% of an external phase (also called the oil phase) which is made with at least one high refractive index (RI in the range of 1.43-1.60) organic ester as described below; a volatile silicone based emulsifier; and a volatile silicone; and (b) 67-85% of an internal phase which is made with 0.5-15%, particularly a minimum of 2% water or salt water; and at least one active ingredient selected from the group consisting of antiperspirant actives (particularly in a glycol solvent), antimicrobials and fragrances, wherein (a) the refractive index of the final cosmetic composition is in the range of 1.42-1.52 and, in a particular embodiment, (b) the conductance of a water droplet applied to the surface of a thin film of the cosmetic composition is at least 250 micro Siemens/cm/ml as measured by the fixed geometry test described below at a loading of at least 7% by weight level of antiperspirant active as measured by a specified test described below, with more particular embodiments having conductances greater than 300 micro Siemens/cm/ml, particularly greater than 400 micro Siemens/cm/ml and especially greater than 500 micro Siemens/cm/ml.
It is important to note that while traditional gels contain on the order of 33-50% water, the emulsions of this composition contain 0.5-15% water.